Structure of thin iron layers on gold substrates

Polycrystalline texturized Au/Fe/Au “sandwiches” are prepared by vacuum deposition on glass substrates. The surface structure and surface roughness are monitored during the layer growth by reflection high energy electron diffraction and soft X-ray reflectometry. The crystalline structure and the relative orientation of gold and iron crystals are determined by transmission electron microscopy. Iron films with thicknesses ranging from 1 to 20 nm have the bulk b.c.c. structure with a (110) plane parallel to the (111) surface plane of the gold crystals. The free surface roughness is constant for very thin iron films and increases when the iron thickness is greater than 1.5 nm.